Glibc is perhaps the only file on a typical Linux sparcv9 system (read: ELF32) that makes use of 64-bit instructions like LDX/STX, and probably does so by using assembler.
How come gcc is not emitting the *X family of instructions when dealing with, for example, operating on uint64_t? The appended piece of sample code will make use of LDX, but only when compiled in ELF64 mode (-m64). With -m32 -mcpu=v9, it still uses the V8 doubleword mechanism and the LDD instruction. The SPARCV9 manual reads: "LDD is provided for compatibility with SPARC-V8. It may execute slowly on SPARC-V9 machines because of data path and register-access difficulties. In some systems it may trap to emulation code. It is suggested that programmers and compilers avoid using these instructions." $ gcc -v Using built-in specs. Target: sparc64-suse-linux Configured with: ../configure --prefix=/usr --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib --libexecdir=/usr/lib --enable-languages=c,c++,objc,fortran,obj-c++,java --enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.4 --enable-ssp --disable-libssp --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' --disable-libgcj --disable-libmudflap --with-slibdir=/lib --with-system-zlib --enable-__cxa_atexit --enable-libstdcxx-allocator=new --disable-libstdcxx-pch --enable-version-specific-runtime-libs --program-suffix=-4.4 --enable-linux-futex --without-system-libunwind --with-cpu=v8 --with-long-double-128 --build=sparc64-suse-linux Thread model: posix gcc version 4.4.1 [gcc-4_4-branch revision 150839] (SUSE Linux) $ gcc-4.5 -v Using built-in specs. COLLECT_GCC=gcc-4.5 COLLECT_LTO_WRAPPER=/usr/lib/gcc/sparc64-suse-linux/4.5/lto-wrapper Target: sparc64-suse-linux Configured with: ../configure --prefix=/usr --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib --libexecdir=/usr/lib --enable-languages=c,c++,objc,fortran,obj-c++,java --enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.5 --enable-ssp --disable-libssp --disable-plugin --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' --disable-libgcj --disable-libmudflap --with-slibdir=/lib --with-system-zlib --enable-__cxa_atexit --enable-libstdcxx-allocator=new --disable-libstdcxx-pch --enable-version-specific-runtime-libs --program-suffix=-4.5 --enable-linux-futex --without-system-libunwind --enable-gold --with-plugin-ld=/usr/bin/gold --with-cpu=v8 --with-long-double-128 --build=sparc64-suse-linux Thread model: posix gcc version 4.5.0 20100209 (experimental) [trunk revision 156621] (SUSE Linux) #include <stdlib.h> #include <stdint.h> extern long long y; long long y = 0x123; uint32_t foo(long long i) { long long x = y+i; return x<<2; } -- Summary: sparcv9 mode does not seem to produce LDX/STX insns Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: target AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: jengelh at medozas dot de GCC build triplet: sparc64-suse-linux-gnu GCC host triplet: sparc64-suse-linux-gnu GCC target triplet: sparc64-suse-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43350
